Mirror substrates, methods of manufacturing the same and display devices including the same

ABSTRACT

A mirror substrate includes a transparent substrate, a plurality of first mirror patterns arranged on the transparent substrate and spaced apart from each other, each of the first mirror patterns including a phase compensation layer and a first mirror layer sequentially stacked on the transparent substrate, and a second mirror layer disposed on the transparent substrate and between neighboring ones of the first mirror patterns, the second mirror layer having a second thickness less than a first thickness of the first mirror layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 USC §119 to Korean PatentApplication No. 10-2016-0006385 filed on Jan. 19, 2016 in the KoreanIntellectual Property Office (KIPO), the disclosure of which isincorporated by reference in its entirety.

BACKGROUND

1. Field

The present disclosure relates to mirror substrates, methods ofmanufacturing the same and display devices including the same. Moreparticularly, the present disclosure relates to mirror substrates havinga plurality of mirror patterns, methods of manufacturing the same anddisplay devices including the same.

2. Description of the Related Art

Various display devices such as an organic light emitting display (OLED)device and a liquid crystal display (LCD) device having a mirrorproperty together with an image display property have been widelyresearched and developed. For example, layer structures or patterns(e.g., mirror patterns) having a reflective property may be inserted tothe display device to realize the mirror property. However, an opticalproperty or a display quality of the display device may be affectedadversely due to an inclusion of the mirror patterns.

SUMMARY

Example embodiments provide a mirror substrate having an improvedoptical property, a method of manufacturing the mirror substrate, and adisplay device including the mirror substrate.

According to some example embodiments, there is provided a mirrorsubstrate that may include a transparent substrate, a plurality of firstmirror patterns arranged on the transparent substrate and spaced apartfrom each other, each of the first mirror patterns including a phasecompensation layer and a first mirror layer sequentially stacked on thetransparent substrate, and a second mirror layer disposed on thetransparent substrate and between neighboring ones of the first mirrorpatterns, the second mirror layer having a second thickness less than afirst thickness of the first mirror layer.

In some example embodiments, the phase compensation layer may include atransparent metal oxide.

In some example embodiments, the phase compensation layer may includeindium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide and/orindium oxide.

In some example embodiments, the mirror substrate may further include acolor control layer interposed between the second mirror layer and thetransparent substrate.

In some example embodiments, the color control layer may include siliconoxide.

In some example embodiments, the first mirror layer may include aluminum(Al), and the second mirror layer may include silver (Ag).

In some example embodiments, a thickness of the phase compensation layermay be greater than a thickness of the color control layer, and thefirst mirror layer may be farther from a surface of the transparentsubstrate than the second mirror layer.

In some example embodiments, the first mirror layer and the secondmirror layer may commonly include Ag.

In some example embodiments, wherein a thickness of the phasecompensation layer may be less than a thickness of the color controllayer, and the second mirror layer may farther from a surface of thetransparent substrate than the first mirror layer.

In some example embodiments, the color control layer may extendcontinuously along surfaces of the first mirror patterns and thetransparent substrate.

In some example embodiments, the second mirror layer may extendcontinuously along surfaces of the first mirror patterns and thetransparent substrate, and a second mirror pattern may include a portionof the second mirror layer formed between the neighboring ones of thefirst mirror patterns.

In some example embodiments, the mirror substrate may further include abarrier layer including a transparent conductive material. The barrierlayer may be disposed on the second mirror layer.

According to some example embodiments a method for manufacturing amirror substrate includes: determining a first thickness and a firstmaterial of a first mirror layer and a second thickness and a secondmaterial of a second mirror layer. A phase difference of reflectedlights from the first mirror layer and the second mirror layer may bemeasured. A thickness of a phase compensation layer may be determinedbased on the measured phase difference. First mirror patterns may beformed on a transparent substrate. Each first mirror pattern may includethe phase compensation layer having the determined thickness and thefirst mirror layer made of the first material having the firstthickness. The second mirror layer made of the second material havingthe second thickness may be formed on the transparent substrate andbetween neighboring ones of the first mirror patterns.

In some example embodiments, the first thickness of the first mirrorlayer may be greater than the second thickness of the second mirrorlayer.

In some example embodiments, a thickness of a color control layerbetween the second mirror layer and the transparent substrate may bedetermined. The thickness of the phase compensation layer may bedetermined in consideration of a change of the phase difference due tothe color control layer.

In some example embodiments, before forming the second mirror layer, thecolor control layer may be formed on the transparent substrate andbetween the neighboring ones of the first mirror patterns. A secondmirror pattern may include the color control layer and the second mirrorlayer.

According to some example embodiments, there is provided a displaydevice that may include a display substrate, a display unit on thedisplay substrate, and a mirror substrate facing the display substratewith respect to the display unit. The mirror substrate may include atransparent substrate, a plurality of first mirror patterns arranged onthe transparent substrate and spaced apart from each other, each of thefirst mirror patterns including a phase compensation layer and a firstmirror layer sequentially stacked on the transparent substrate, and asecond mirror layer disposed on the transparent substrate and betweenneighboring ones of the first mirror patterns, the second mirror layerhaving a second thickness less than a first thickness of the firstmirror layer.

In some example embodiments, the display unit may include an emittingregion including a pixel electrode and an emitting layer, and anon-emitting region. The non-emitting region may overlap the firstmirror patterns, and the emitting region may overlap the second mirrorlayer.

In some example embodiments, the mirror substrate may further include acolor control layer interposed between the transparent substrate and thesecond mirror layer.

In some example embodiments, the first mirror layer may include aluminum(Al) or silver (Ag), the second mirror layer may include Ag, the colorcontrol layer may include silicon oxide, and the phase compensationlayer may include a transparent metal oxide.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments are more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings. FIGS. 1 to 18 represent non-limiting example embodiments asdescribed herein:

FIG. 1 is a cross-sectional view illustrating a mirror substrate inaccordance with example embodiments;

FIG. 2 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments;

FIGS. 3 and 4 are cross-sectional views illustrating mirror substratesin accordance with some example embodiments;

FIG. 5 is a cross-sectional view illustrating a mirror substrate inaccordance with example embodiments;

FIG. 6 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments;

FIG. 7 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments;

FIG. 8 is a flow chart illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments;

FIGS. 9, 10 and 11 are cross-sectional views illustrating a method ofmanufacturing a mirror substrate in accordance with example embodiments;

FIG. 12 is a flow chart illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments;

FIGS. 13 and 14 are cross-sectional views illustrating a method ofmanufacturing a mirror substrate in accordance with example embodiments;

FIG. 15 is a schematic cross-sectional view illustrating a displaydevice in accordance with example embodiments; and

FIGS. 16, 17 and 18 are enlarged cross-sectional views of a portiondesignated as “A” of FIG. 15.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Various example embodiments are described more fully hereinafter withreference to the accompanying drawings, in which some exampleembodiments are shown. The present disclosure may, however, be embodiedin many different forms and should not be construed as limited to theexample embodiments set forth herein. Rather, these example embodimentsare provided so that the present disclosure is thorough and complete,and fully conveys the scope of the present inventive concept to thoseskilled in the art. In the drawings, the sizes and relative sizes oflayers and regions may be exaggerated for clarity. Like numerals referto like elements throughout.

It is understood that, although the terms first, second, third etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are used to distinguish oneelement from another. Thus, a first element discussed below could betermed a second element without departing from the teachings of thepresent disclosure. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It is understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or one or more interveningelements may be present. In contrast, when an element is referred to asbeing “directly connected” or “directly coupled” to another element,there may be no intervening elements present. Other terms used todescribe the relationship between elements should be interpreted in alike fashion (e.g., “between” versus “directly between,” “adjacent”versus “directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of thepresent disclosure. As used herein, the singular forms “a,” “an,” and“the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It is further understood that theterms “comprises” and/or “comprising,” when used in the specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but may not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art. It is further understood that terms, suchas those defined in commonly used dictionaries, should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthe relevant art and should not be interpreted in an idealized or overlyformal sense unless expressly so defined herein.

FIG. 1 is a cross-sectional view illustrating a mirror substrate inaccordance with example embodiments. The mirror substrate may include atransparent substrate 100 and mirror layers. The transparent substrate100 may be provided as an encapsulation substrate of a display device.The transparent substrate 100 may include a glass substrate or atransparent plastic substrate.

The transparent substrate 100 may include a first surface 100 a and asecond surface 100 b. The mirror layers may be disposed on the firstsurface 100 a. A viewer of the display device may be toward the secondsurface 100 b.

The mirror layer may include a first mirror layer 120 and a secondmirror layer 140. A plurality of the first mirror layers 120 and thesecond mirror layers 140 may be arranged alternately and repeatedlyalong a horizontal direction on the first surface 100 a of thetransparent substrate 100.

A phase compensation layer 110 may be interposed between the firstmirror layer 120 and the first surface 100 a of the substrate 100. Forexample, the phase compensation layer 110 may contact the first surface100 a and a bottom surface of the first mirror layer 120.

In some example embodiments, a first mirror pattern 130 may include thefirst mirror layer 120 and the phase compensation layer 110. A secondmirror pattern may include the second mirror layer 140. The first mirrorpattern 130 and the second mirror pattern may be arranged alternatelyand repeatedly on the first surface 100 a.

In some example embodiments, the first mirror layer 120 and the secondmirror layer 140 may include different metals. Further, a thickness ofthe first mirror layer 120 may be greater than that of the second mirrorlayer 140.

In some embodiments, a metal included in the first mirror layer 120 (afirst metal) may have a refractive index in a visible light wavelengthrange that is greater than that of a metal included in the second mirrorlayer 140 (a second metal). In some embodiments, a metal cheaper thanthe second metal may be selected as the first metal from an economicaspect, because the first mirror layer 120 may be thicker than thesecond mirror layer 140. In some example embodiments, the first mirrorlayer 120 may include aluminum (Al), and the second mirror layer 140 mayinclude silver (Ag).

If the mirror substrate is applied to the display device, the secondmirror pattern including the second mirror layer 140 may face anemitting region of the display device. The first mirror pattern 130 mayface a non-emitting region of the display device, and a reflectiveproperty or a mirror property may be realized by the first mirrorpattern 130.

The phase compensation layer 110 may be interposed between the firstmirror layer 120 and the transparent substrate 100, and a phasedifference between reflected lights from the first mirror layer 120 andthe second mirror layer 140 may be compensated. As described above, thefirst mirror layer 120 and the second mirror layer 140 may includedifferent metals and/or different thicknesses to cause the phasedifference of the reflected lights. Accordingly, the reflective propertyof the mirror substrate and a display quality of the display deviceincluding the mirror substrate may be degraded due to an interference ofthe reflected lights.

In some embodiments, if the first metal includes Al, and the secondmetal includes Ag, the first mirror layer 120 and the second mirrorlayer 140 may have different penetration depths of light. For example,the penetration depth of the first mirror layer 120 may be less thanthat of the second mirror layer 140. In this case, an incident light tothe transparent substrate 100 may be reflected at a position relativelyadjacent to a surface of the first mirror layer 120 including Al, andmay be reflected at a position relatively adjacent to an inside of thesecond mirror layer 140 including Ag. Thus, the phase difference of thereflected lights may be caused by the differences of the reflectedpositions and/or the reflected depths.

In some example embodiments, a thickness of the phase compensation layer110 may be determined in consideration of an extent of the phasedifference. For example, a phase of the reflected light from the firstmirror pattern 130 may be matched or coordinated with a phase of thereflected light from the second mirror pattern or the second mirrorlayer 140.

In some example embodiments, the phase compensation layer 110 may betransmissive, and may include a material that may be patterned togetherwith the first mirror layer 120. In some embodiments, the phasecompensation layer 110 may include a transparent metal oxide or atransparent conductive material, for example, indium tin oxide (ITO),indium zinc oxide (IZO), zinc oxide or indium oxide, or the like.

As described above, the phase compensation layer 110 may be included inthe first mirror pattern 130. The phase compensation layer 110 is usedto correct the phase difference from the reflected light by the secondmirror layer 140. Therefore, the mirror substrate and the display devicehaving improved reflective property and display quality may be achieved.

FIG. 2 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments. The mirror substrateillustrated in FIG. 2 may have elements and/or constructionssubstantially the same as or similar to those illustrated in FIG. 1except for a structure of a second mirror pattern. Thus, detaileddescriptions on repeated elements and/or structure may be omitted.

Referring to FIG. 2, a second mirror pattern 150 may include a colorcontrol layer 142 and a second mirror layer 144 sequentially stacked onthe first surface 100 a of the transparent substrate 100. As describedabove, if the second mirror pattern 150 of the mirror substrate faces anemitting region of a display device, light emitting from the displaydevice may penetrate through the second mirror pattern 150 to bevisualized to the viewer. The color control layer 142 may be interposedbetween the second mirror layer 144 and the transparent substrate 100 tocontrol a color impression of the display light. In some embodiments,the color control layer 142 may include an inorganic oxide-basedmaterial, for example, silicon oxide, silicon oxynitride, or the like.

As described with reference to FIG. 1, the first mirror layer 120 mayinclude Al, and the second mirror layer 144 may include Ag. A phasedifference between reflected lights from the first mirror pattern 130and second mirror pattern 150 may become greater than that the phasedifference in the mirror substrate FIG. 1 due to an inclusion of thecolor control layer 142 in the second mirror pattern 150.

In some embodiments, a thickness of the phase compensation layer 110included in the first mirror pattern 130 may become greater than thatincluded in the mirror substrate of FIG. 1. In some embodiments, thephase compensation layer 110 may be thicker than the color control layer142. A bottom surface of the first mirror layer 120 may be higher than abottom surface of the second mirror layer 144 from the first surface 100a of the transparent substrate 100. In this case, the second mirrorlayer 144 may be nearer to a viewer than the first mirror layer 120.

FIGS. 3 and 4 are cross-sectional views illustrating mirror substratesin accordance with some example embodiments. For example, FIG. 3 andFIG. 4 illustrate modifications of second mirror patterns illustrated inFIG. 1 and FIG. 2, respectively.

Referring to FIG. 3, a second mirror layer 141 may extend continuouslyand conformally along surfaces of the first mirror patterns 130 and thefirst surface 100 a of the transparent substrate 100. In some exampleembodiments, a portion of the second mirror layer 141 formed between theneighboring first mirror patterns 130 and contacting the first surface100 a of the transparent substrate 100 may substantially serve as asecond mirror pattern. In some embodiments, a portion of the secondmirror layer 141 contacting the first mirror pattern 130 may also serveas the first mirror pattern 130 together with the first mirror layer120.

Referring to FIG. 4, a color control layer 143 and a second mirror layer145 may extend continuously and conformally along surfaces of the firstmirror patterns 130 and the first surface 100 a of the transparentsubstrate 100. In some example embodiments, portions of the colorcontrol layer 143 and the second mirror layer 145 formed between theneighboring first mirror patterns 130 may substantially serve as asecond mirror pattern 152. In some embodiments, portions of the colorcontrol layer 143 and the second mirror layer 145 disposed on the firstmirror pattern 130 may also serve as the first mirror pattern 130together with the first mirror layer 120.

FIG. 5 is a cross-sectional view illustrating a mirror substrate inaccordance with example embodiments. The mirror substrate may includefirst mirror patterns 135 and second mirror patterns 160 alternately andrepeatedly arranged along a horizontal direction on the first surface100 a of the transparent substrate 100. The first mirror patterns 135may include a phase compensation layer 115 and a first mirror layer 125sequentially stacked on the first surface 100 a of the transparentsubstrate 100. The second mirror pattern 160 may include a color controllayer 165 and a second mirror layer 163 sequentially stacked on thefirst surface 100 a of the transparent substrate 100.

In some example embodiments, the first mirror layer 125 and the secondmirror layer 163 may include the same metal. For example, the first andsecond mirror layers 125 and 163 commonly include Ag. As illustrated inFIG. 5, the first mirror layer 125 and the second mirror layer 163 maybe merged with each other as a single or unitary member.

A phase difference that may be caused due to an inclusion of differentmetals may be reduced because the first mirror layer 125 and the secondmirror layer 163 may include the same metal. However, the color controllayer 165 that is used to control a color impression at an emittingregion may still contribute to the phase difference.

The phase difference may be corrected or canceled by the phasecompensation layer 115 included in the first mirror pattern 135. Athickness of the phase compensation layer 115 may be determined inconsideration of an extent of the phase difference caused by the colorcontrol layer 165.

In some example embodiments, if the first mirror layer 125 and thesecond mirror layer 163 include the same metal, a thickness of the phasecompensation layer 115 may become smaller than that of the mirrorsubstrate of FIG. 2. In some embodiments, the thickness of the phasecompensation layer 115 may be smaller than a thickness of the colorcontrol layer 165. In this case, a bottom surface of the first mirrorlayer 125 may be lower than a bottom surface of the second mirror layer163 from the first surface 100 a of the transparent substrate 100. Thus,the first mirror layer 125 may be nearer to a viewer than the secondmirror layer 163. As described above, the phase compensation layer 115may include a transparent conductive material, for example, ITO, IZO, orthe like.

FIG. 6 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments. The mirror substrateillustrated in FIG. 6 may have elements and/or constructionssubstantially the same as or similar to those illustrated in FIG. 5except for a structure of a second mirror pattern. Thus, detaileddescriptions on repeated elements and/or structure may be omitted.

Referring to FIG. 6, a color control layer 166 may extend continuouslyand conformally along surfaces of the first mirror patterns 135 and thefirst surface 100 of the transparent substrate 100. A second mirrorlayer 164 may be individually patterned on a portion of the colorcontrol layer 166 between the neighboring first mirror patterns 135. Asecond mirror pattern 167 may include the second mirror layer 164 andthe portion of the color control layer 166 between the neighboring firstmirror patterns 135.

In some example embodiments, the second mirror layer 164 may also have aconformal profile substantially the same as or similar to that of thecolor control layer 166. In this case, portions of the second mirrorlayer 164 and the color control layer 166 between the neighboring firstmirror patterns 135 may substantially serve as a second mirror pattern.Portions of the second mirror layer 164 and the color control layer 166formed on the first mirror pattern 135 may also serve as the firstmirror pattern 135 together with the first mirror layer 125.

FIG. 7 is a cross-sectional view illustrating a mirror substrate inaccordance with some example embodiments. The mirror substrate mayinclude the first mirror layers 120 and second mirror layers 140alternately and repeatedly arranged on the first surface 100 a of thetransparent substrate 100. The phase compensation layer 110 may beinterposed between the first mirror layer 120 and the transparentsubstrate 100 such that the first mirror pattern 130 may include thephase compensation layer 110 and the first mirror layer 120.

In some example embodiments, a barrier layer 170 may be disposed on thesecond mirror layer 140. The barrier layer 170 may prevent a metallicmaterial included in the second mirror layer 140 from being diffused toan emitting region of a display device. In some embodiments, the barrierlayer 170 may include a transparent metal oxide or a transparentconductive material such as ITO or IZO. In some embodiments, the barrierlayer 170 may also extend continuously on the first mirror patterns 130.The barrier layer 170 may be also applied to the mirror substratesillustrated with reference to FIGS. 1 to 6.

FIG. 8 is a flow chart illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments. FIGS. 9 to 11 arecross-sectional views illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments.

Referring to FIG. 8, in operation S10, materials and thicknesses of afirst mirror layer and a second mirror layer may be determined. In someexample embodiments, a first metal and a second metal may be determinedfor the first mirror layer and the second mirror layer, respectively.For example, the first metal and the second metal may be determined asAl and Ag, respectively. In some embodiments, a common metal, forexample, Ag may be determined for the first mirror layer and the secondmirror layer. In some example embodiments, a thickness of the firstmirror layer may be determined to be greater than that of the secondmirror layer.

In operation S20, a phase difference between reflected lights from thefirst mirror layer and the second mirror layer may be measured based onthe materials and the thicknesses determined in the operation S10. Insome embodiments, if the first mirror layer and the second mirror layerinclude Al and Ag, respectively, a penetration depth of incident lightin the second mirror layer may be greater than that in the first mirrorlayer, and thus the phase difference of the reflected lights may begenerated.

In operation S30, a thickness of a phase compensation layer that isformed between the first mirror layer and a transparent substrate may bedetermined based on the phase difference measured in the operation S20.In some example embodiments, the thickness of the phase compensationlayer may be determined so that a phase of the reflected light from thefirst mirror layer may be corrected by the phase compensation layer tomatch a phase of the reflected light from the second mirror layer.

Referring to FIGS. 9 and 10, in operation S40, a first mirror pattern130 including the phase compensation layer 110 having the thicknessdetermined in the operation S30, and the first mirror layer 120 may beformed on a transparent substrate 100. In some example embodiments, asillustrated in FIG. 9, a preliminary phase compensation layer 103 and apreliminary first mirror layer 105 may be formed sequentially on thetransparent substrate 100. The phase compensation layer 103 may beformed of a transparent metal oxide such as ITO or IZO. The preliminaryfirst mirror layer 105 may be formed of a metal such as Al or Ag. Insome embodiments, the preliminary phase compensation layer 103 and thepreliminary first mirror layer 105 may be formed by a depositionprocess, for example, a sputtering process, an atomic layer deposition(ALD) process, a chemical vapor deposition (CVD) process, etc. In otherembodiments, the preliminary phase compensation layer 103 and thepreliminary first mirror layer 105 may be formed by an in-situdeposition process.

The preliminary phase compensation layer 103 and the preliminary firstmirror layer 105 may be formed to have the materials and the thicknessesof the phase compensation layer 110 and the first mirror layer 120 aspre-determined in the operations S10 and S30.

As illustrated in FIG. 10, the preliminary first mirror layer 105 andthe preliminary phase compensation layer 103 may be patterned to form aplurality of the first mirror patterns 130. The first mirror patterns130 may be arranged on the transparent substrate 100 along thehorizontal direction to be spaced apart from each other. In some exampleembodiments, the preliminary first mirror layer 105 and the preliminaryphase compensation layer 103 may be patterned by substantially the sameetching process. For example, the preliminary first mirror layer 105 andthe preliminary phase compensation layer 103 may be etched concurrentlyby a plasma etching process.

Referring to FIGS. 8 and 11, in operation S50, the second mirror layer140 may be formed between the neighboring first mirror patterns 130. Insome example embodiments, the second mirror layer 140 may be formed of ametal by a sputtering process or an ALD process. In some embodiments,the second mirror layer 140 may be formed of Ag. The second mirror layer140 may be formed to have the thickness determined in the operation S10,and may be thinner than the first mirror layer 120.

In some example embodiments, as illustrated in FIG. 11, the secondmirror layer 140 may be individually patterned between the neighboringfirst mirror patterns 130. In this case, the second mirror layer 140 maybe formed by a printing process using a conductive paste, or adeposition process using a slit mask. In some example embodiments, asillustrated in FIG. 3, the second mirror layer may be formed to extendcontinuously and conformally on surfaces of the first mirror patterns130. Subsequently, as illustrated in FIG. 7, a barrier layer including,for example, ITO may be further formed on the second mirror layer 140.

FIG. 12 is a flow chart illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments. FIGS. 13 and 14 arecross-sectional views illustrating a method of manufacturing a mirrorsubstrate in accordance with example embodiments. Detailed descriptionson processes substantially the same as or similar to those describedwith reference to FIG. 8 and FIGS. 9 to 11 may be omitted.

Referring to FIG. 12, in operation S15, materials and thicknesses offirst and second mirror layers may be determined. In some embodiments,the first mirror layer and the second mirror layer may include differentmetals such as Al and Ag, respectively. In some embodiments, the firstand second mirror layer may be determined to include a common metal suchas Ag. As described above, the thickness of the first mirror layer maybe determined to be greater than the thickness of the second mirrorlayer.

In operation S25, a thickness of a color control layer that is formedbetween the second mirror layer and a transparent substrate may bedetermined.

In operation S35, a phase difference between reflected lights from thefirst mirror layer and the second mirror layer may be measured. Aninsertion of the color control layer under the second mirror layer maycontribute to the phase difference. Accordingly, the phase differencemay become greater than that measured in the operation S20 of FIG. 8

In operation S45, a thickness of a phase compensation layer that isformed between the first mirror layer and the transparent substrate maybe determined based on the phase difference measured in the operationS35. For example, the thickness of the phase compensation layer may bedetermined to be greater than that determined in the operation S30 ofFIG. 8 due to the addition of the color control layer.

In some embodiments, if the first mirror layer and the second mirrorlayer include Al and Ag, respectively, the thickness of the phasecompensation layer may be determined to be greater than the thickness ofthe color control layer. In some embodiments, if the first mirror layerand the second mirror layer commonly Ag, the thickness of the phasecompensation layer may be determined to be smaller than the thickness ofthe color control layer.

Referring FIGS. 12 and 13, in operation S55, a first mirror pattern 130including the phase compensation layer 110 having the thicknessdetermined in the operation S45 and the first mirror layer 120 may beformed on the transparent substrate 100. The first mirror pattern 130may be formed by processes substantially the same as or similar to thosedescribed with reference to FIGS. 9 and 10. As described above, thephase compensation layer 110 may be formed of a transparent metal oxidesuch as ITO or IZO.

Referring FIGS. 12 and 14, in operation S65, a second mirror pattern 150including the color control layer 142 and the second mirror layer 144may be formed between the first mirror patterns 130. The second mirrorlayer 144 and the color control layer 142 may be formed to have thethicknesses determined in the operations S15 and S25, respectively.

In some example embodiments, the color control layer 142 may be formedof an inorganic oxide-based material such as silicon oxide or siliconoxynitride. If the second mirror layer 144 includes the same metal asthat of the first mirror layer 120, the first and second mirror layersmay be substantially merged with each other as illustrated in FIG. 5. Insome embodiments, as illustrated in FIG. 14, the second mirror patterns150 may be individually formed between the neighboring first mirrorpatterns 130 to be spaced apart from each other. In some embodiments,the color control layer and/or the second mirror layer may also extendon surfaces of the first mirror patterns 130 as illustrated in FIG. 4 orFIG. 6. Subsequently, as illustrated in FIG. 7, a barrier layer may befurther formed on the second mirror layer 144.

According to some example embodiments as described above, a thickness ofa phase compensation layer included in a first mirror pattern may bepre-determined in consideration of a phase matching with a reflectedlight from a second mirror layer or a second mirror pattern. Based onthe pre-determined thickness, the first mirror layer and the phasecompensation layer may be formed using materials that may be capable ofbeing deposited and etched by the same deposition and etching processes.Therefore, a process productivity may be enhanced while improving adisplay quality and a reflective property of a display device and/or amirror substrate.

FIG. 15 is a schematic cross-sectional view illustrating a displaydevice in accordance with example embodiments. FIGS. 16 to 18 areenlarged cross-sectional views of a portion designated as “A” of FIG.15. Detailed descriptions on elements and/or materials substantially thesame as or similar to those described with reference to FIGS. 1 to 7 maybe omitted.

Referring to FIGS. 15 and 16, the display device may include a displayunit 300 disposed on a display substrate 200, and a mirror substrate 190facing the display substrate 200 with respect to the display unit 300.In some example embodiments, the mirror substrate 190 may havestructures and/or constructions substantially the same as or similar tothose illustrated with reference to FIG. 1. As described above, themirror substrate 190 may include a first mirror pattern 130 and a secondmirror layer 140 alternately and repeatedly arranged on a first surface100 a of a transparent substrate 100. The first mirror pattern 130 mayinclude a phase compensation layer 110 and a first mirror layer 120sequentially stacked from the first surface 100 a.

A sealing member 180 may be interposed between the transparent substrate100 and the display substrate 200 such that the display unit 300 may beencapsulated. Thus, the mirror substrate 190 may substantially serve asan encapsulation substrate.

In some embodiments, the sealing member 180 may be in contact with thesecond mirror layer 140 at a peripheral region of the mirror substrate190. In this case, the first mirror pattern 130 at the peripheral regionmay serve as an align key. In other embodiments, the sealing member 180may be in contact with the first mirror pattern 130 or the first surface100 a.

As illustrated in FIG. 16, the display unit 300 may include a switchingdevice on the display substrate 200, and a display structureelectrically connected to the switching device. The display unit 300 mayfurther include a wiring structure such as a scan line, a data line, apower line, etc. that may be electrically connected to the switchingdevice and/or the display structure. An insulation structure coveringthe switching device and/or the wiring structure may be also included inthe display unit 300. The insulation structure may include, for example,a barrier layer 210, an insulating interlayer 230, and a via insulationlayer 250.

The switching device may include a thin film transistor (TFT) includingan active pattern 215, a gate insulation layer 220, a gate electrode225, a source electrode 243 and a drain electrode 245. The displaystructure may include a first electrode 260, a display 280, and thesecond electrode 290. The display substrate 200 may include a glasssubstrate, a transparent plastic substrate or a flexible plasticsubstrate.

The barrier layer 210 may be formed on an upper surface of the displaysubstrate 200. Moisture penetrating through the display substrate 200may be blocked by the barrier layer 210, and impurity diffusion betweenthe display substrate 200 and structures thereon may be also blocked bythe barrier layer 210.

For example, the barrier layer 210 may include silicon oxide, siliconnitride, or silicon oxynitride. These may be used alone or in acombination thereof. In an embodiment, the barrier layer 210 may have amulti-layered structure including a silicon oxide layer and a siliconnitride layer.

The active pattern 215 may include a silicon-based semiconductorcompound such as polysilicon. In some embodiments, the active pattern215 may include an oxide semiconductor such as indium gallium zinc oxide(IGZO), zinc tin oxide (ZTO), or indium tin zinc oxide (ITZO). Forexample, the active layer 215 including the silicon compound or theoxide semiconductor may be formed by a sputtering process, and then maybe patterned by a photo-lithography process.

The gate insulation layer 220 may be formed on the barrier layer 210,and cover the active pattern 215. The gate insulation layer 220 mayinclude silicon oxide, silicon nitride, and/or silicon oxynitride. Thegate insulation layer 220 may have a multi-layered structure including asilicon oxide layer and a silicon nitride layer.

The gate electrode 225 may be formed on the gate insulation layer 220,and may be superimposed over the active pattern 215. For example, afirst conductive layer may be formed on the gate insulation layer 220,and may be patterned by a photo-lithography process to form the gateelectrode 225. The first conductive layer may be formed of a metal suchas Al, Ag, W, Cu, Mo, Ti, Ta, Cr, etc., or a nitride thereof by asputtering process or an ALD process. The first conductive layer may beformed as a multi-layered structure such as an Al/Mo structure or aTi/Cu structure. In some embodiments, the scan line may be also formedfrom the first conductive layer. The gate electrode 225 may diverge fromthe scan line.

In some embodiments, an ion-implantation process may be performed usingthe gate electrode 225 as an implantation mask to form a source regionand a drain region at both ends of the active pattern 215. A portion ofthe active pattern 215 between the source and drain regions that mayoverlap the gate electrode 225 may be defined as a channel regionthrough which a charge may be moved or transferred.

The insulating interlayer 230 may be formed on the gate insulation layer220, and may cover the gate electrode 225. The insulating interlayer 230may include silicon oxide, silicon nitride, and/or silicon oxynitride.The insulating interlayer 230 may have a multi-layered structureincluding a silicon oxide layer and a silicon nitride layer.

The source electrode 243 and the drain electrode 245 may extend throughthe insulating interlayer 230 and the gate insulation layer 220 tocontact with the active pattern 215. The source electrode 243 and thedrain electrode 245 may be in contact with the source region and thedrain region, respectively, of the active pattern 215.

For example, the insulating interlayer 230 and the gate insulation layer220 may be partially etched to form contact holes through which theactive pattern 215 may be exposed. A second conductive layer filling thecontact holes may be formed on the insulating interlayer 230, and may bepatterned by a photo-lithography process to form the source electrode243 and the drain electrode 245. The second conductive layer may beformed from a material and a process substantially the same as orsimilar to those to form the first conductive layer.

In some embodiments, a data line may be also formed from the secondconductive layer. In this case, the source electrode 243 may divergefrom the data line.

The TFT may be formed in each pixel of the display unit by the processesas described above. In some embodiments, at least two TFTs and acapacitor may be formed in each pixel.

The via insulation layer 250 may be formed on the insulating interlayer230, and may cover the source and drain electrodes 243 and 245. The viainsulation layer 250 may be formed using an organic material such aspolyimide, an epoxy resin, an acrylate-based resin, or polyester by aspin coating process or a slit coating process. The via insulation layer250 may also serve as a planarization layer of the display unit 300.

The display structure may be formed on the via insulation layer 250. Thefirst electrode 260 may extend through the via insulation layer 250, andmay be electrically connected to the drain electrode 245. For example,the via insulation layer 250 may be partially etched to form a via holethrough which the drain electrode 245 may be exposed. A third conductivelayer sufficiently filling the via hole may be formed on the viainsulation layer 250, and may be patterned by a photo-lithographyprocess to form the first electrode 260. The first electrode 260 mayserve as an anode or a pixel electrode of the display unit 300, and maybe formed per each pixel included in the display unit 300.

The third conductive layer may be formed from a material and a processsubstantially the same as or similar to those to form the firstconductive layer. In some embodiments, the third conductive layer may beformed of a transparent conductive layer such as indium tin oxide (ITO),indium zinc oxide (IZO), zinc oxide, indium oxide, etc.

A pixel defining layer (PDL) 270 may be formed on the via insulationlayer 250 to cover a peripheral portion of the first electrode 260. Forexample, the PDL 270 may be formed using a photosensitive organicmaterial by exposure and developing processes. Alternatively, the PDL270 may be formed of a silicon-based inorganic material by aphoto-lithography process. In some example embodiments, an area of thefirst electrode 260 exposed by the PDL 270 may substantially correspondto an emitting region of each pixel.

The display layer 280 may be formed on the first electrode 260 and thePDL 270. In some example embodiments, the display layer 280 may includean organic light emitting material, and the display device may beprovided as an OLED device. In this case, a hole transport layer (HTL)and an electron transport layer (ETL) may be further formed under thedisplay layer 280 and on the display layer 280, respectively. Forexample, the display layer 280 may be formed by individually printingthe organic light emitting material at each pixel through a fine metalmask (FMM). The HTL and the ETL may be formed at each pixel, or may beformed commonly at a plurality of the pixels.

In some embodiments, a liquid crystal material may be used for thedisplay layer 280. In this case, the display device may be provided asan LCD device.

The second electrode 290 may be formed on the PDL 270 and the displaylayer 280. In some embodiments, the second electrode 290 may serve as acommon electrode formed on the plurality of the pixels. The secondelectrode 290 may also serve as a cathode of the display unit 300. Insome embodiments, the second electrode 290 may be formed commonly on theemitting region and a non-emitting region of the display unit 300. Thesecond electrode 290 may be formed by a depositing a metal or atransparent conductive material as mentioned above through, for example,an open mask.

The display unit 300 may be formed on the display substrate 200, and themirror substrate 190 may be formed on the display substrate 200 usingthe sealing member 180 such that the mirror substrate 190 and thedisplay substrate 200 may face each other. As illustrated in FIG. 16,the second mirror layer 140 of the mirror substrate 190 maysubstantially overlap the emitting region of the display unit 300. Thesecond mirror layer 140 having a relatively small thickness may face theemitting region so that a display property may be substantiallyrealized.

In some embodiments, the barrier layer 170 as illustrated in FIG. 7 maybe further formed on the second mirror layer 140. For example, thebarrier layer 170 blocks a metallic material included in the secondmirror layer 140 from being diffused to the display unit 300. Thenon-emitting region of the display unit 300 may substantially overlapthe first mirror pattern 130 of the mirror substrate 190. In someembodiments, the first mirror pattern 130 may substantially overlap thePDL 270.

A mirror property may be realized on the non-emitting region by thefirst mirror layer 120 that may have relatively large refractive index,reflectivity and thickness. Additionally, the phase compensation layer110 may correct a phase difference from a reflected light at the secondmirror layer 140 to achieve an improved reflective property. In someembodiments, as illustrated in FIG. 3, the second mirror layer may bealso formed conformally on surfaces of the first mirror patterns 130.

Referring to FIG. 17, a color control layer 142 may be included in aportion of the mirror substrate overlapping the emitting region.Accordingly, the color control layer 142 may adjust a color impressionof light generated from the emitting region. A second mirror pattern 150may include the color control layer 142 and a second mirror layer 144,and may overlap the emitting region.

A thickness of the phase compensation layer 110 of the first mirrorpattern 130 may be further increased in consideration of a phasedifference contributed by the color control layer 142. In some exampleembodiments, if the first mirror layer 120 and the second mirror layer144 include Al and Ag, respectively, the thickness of the phasecompensation layer 110 may be greater than that of the color controllayer 142. Thus, the second mirror layer 144 may be nearer to a viewerthan the first mirror layer 120. In some embodiments, as illustrated inFIG. 4, the color control layer and the second mirror layer may be alsoformed conformally on surfaces of the first mirror patterns 130.

Referring to FIG. 18, the first mirror layer 125 and the second mirrorlayer 163 may commonly include a metal, for example, Ag. In this case,the first and second mirror layers 125 and 163 may be merged with eachother. The phase compensation layer 115 and the color control layer 165may be included in the first mirror pattern 135 and the second mirrorpattern 160, respectively, and the phase compensation layer 115 may bethinner than the color control layer 165. Accordingly, the first mirrorlayer 125 may be nearer to a viewer than the second mirror layer 163. Insome embodiments, as illustrated in FIG. 6, the color control layer 165may be also formed conformally along surfaces of the first mirrorpatterns 130. The second mirror layer may be also formed conformallyalong the surfaces of the first mirror patterns 130 on the color controllayer 165.

Hereinafter, properties of the mirror substrate according to someexample embodiments are described in more detail with reference toExperimental Examples.

Experimental Example 1

A first mirror layer having a thickness of 1,000 Å and including Al wasformed on a first region (i.e., a first mirror region) of a glasssubstrate. A second mirror layer having a thickness of 1,000 Å andincluding Ag, and a barrier layer having a thickness of 150 Å andincluding ITO were formed on a second region (i.e., a second mirrorregion) of the glass substrate.

A visible light having a wavelength of 530 nm was introduced to thefirst mirror layer and the second mirror layer, and phases of thereflected lights therefrom were measured. For example, the phases of thereflected lights from the first mirror layer and the second mirror layerwere −135° and −113°, respectively, and thus a phase difference wasabout 22°.

Subsequently, a phase compensation layer including ITO was formedbetween the glass substrate and the first mirror layer to correct thephase difference. A phase of a reflected light from the first mirrorlayer became consistent with that from the second mirror layer byforming the phase compensation layer having a thickness of 127 Å.

Experimental Example 2

A first mirror layer having a thickness of 1,000 Å and including Al wasformed on a first region of a glass substrate. A color control layerhaving a thickness of 300 Å and including silicon oxide (SiO₂), a secondmirror layer having a thickness of 250 Å and including Ag, and a barrierlayer having a thickness of 150 Å and including ITO were sequentiallyformed on a second region of the glass substrate.

A phase difference of reflected lights from the first mirror layer andthe second mirror layer was measured in the same method as that inExperimental Example 1, and the phase difference was about 95°.

Subsequently, a phase compensation layer including ITO was formedbetween the glass substrate and the first mirror layer to correct thephase difference. A phase of a reflected light from the first mirrorlayer became consistent with that from the second mirror layer byforming the phase compensation layer having a thickness of 386 Å.

Experimental Example 3

A first mirror layer having a thickness of 1,000 Å and including Ag wasformed on a first region of a glass substrate. A color control layerhaving a thickness of 300 Å and including silicon oxide, a second mirrorlayer having a thickness of 150 Å and including Ag, and a barrier layerhaving a thickness of 150 Å and including ITO were sequentially formedon a second region of the glass substrate.

A phase difference of reflected lights from the first mirror layer andthe second mirror layer was measured in the same method as that inExperimental Example 1, and the phase difference was about 80°.

Subsequently, a phase compensation layer including ITO was formedbetween the glass substrate and the first mirror layer to correct thephase difference. A phase of a reflected light from the first mirrorlayer became consistent with that from the second mirror layer byforming the phase compensation layer having a thickness of 285 Å.

According to some example embodiments of the present disclosure, in amirror substrate including first and second mirror layers of differentthicknesses, a phase compensation layer may be inserted so that phasesof reflected lights from the first and second mirror layers may becomeconsistent with each other. Thus, a reflective property from the mirrorsubstrate may be improved. A thickness of the phase compensation layermay be finely adjusted in consideration of materials of the first andsecond mirror layers, and an addition of a color control layer, and thusa display quality and a reflective property of a display deviceincluding the mirror substrate may be optimized.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although some example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications and deviations are possible in the exampleembodiments without materially departing from the novel teachings andadvantages of the present disclosure. Accordingly, such modificationsare intended to be included within the scope of the present disclosure.Therefore, it is to be understood that the foregoing is illustrative ofvarious example embodiments and is not to be construed as limited to thespecific example embodiments disclosed, and that modifications to thedisclosed example embodiments, as well as other example embodiments, areintended to be included within the scope of the present disclosure.

What is claimed is:
 1. A mirror substrate, comprising: a transparentsubstrate; a plurality of first mirror patterns arranged on thetransparent substrate and spaced apart from each other, each of thefirst mirror patterns including a phase compensation layer and a firstmirror layer sequentially stacked on the transparent substrate; and asecond mirror layer disposed on the transparent substrate and betweenneighboring ones of the first mirror patterns, the second mirror layerhaving a second thickness less than a first thickness of the firstmirror layer.
 2. The mirror substrate of claim 1, wherein the phasecompensation layer includes a transparent metal oxide.
 3. The mirrorsubstrate of claim 2, wherein the phase compensation layer includes atleast one of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxideor indium oxide.
 4. The mirror substrate of claim 2, further comprisinga color control layer interposed between the second mirror layer and thetransparent substrate.
 5. The mirror substrate of claim 4, wherein thecolor control layer includes silicon oxide.
 6. The mirror substrate ofclaim 4, wherein the first mirror layer includes aluminum (Al), and thesecond mirror layer includes silver (Ag).
 7. The mirror substrate ofclaim 6, wherein a thickness of the phase compensation layer is greaterthan a thickness of the color control layer, and the first mirror layeris farther from a surface of the transparent substrate than the secondmirror layer.
 8. The mirror substrate of claim 4, wherein the firstmirror layer and the second mirror layer commonly include Ag.
 9. Themirror substrate of claim 8, wherein a thickness of the phasecompensation layer is less than a thickness of the color control layer,and the second mirror layer is farther from a surface of the transparentsubstrate than the first mirror layer.
 10. The mirror substrate of claim4, wherein the color control layer extends continuously along surfacesof the first mirror patterns and the transparent substrate.
 11. Themirror substrate of claim 1, wherein the second mirror layer extendscontinuously along surfaces of the first mirror patterns and thetransparent substrate, and a second mirror pattern includes a portion ofthe second mirror layer formed between the neighboring ones of the firstmirror patterns.
 12. The mirror substrate of claim 1, further comprisinga barrier layer including a transparent conductive material, the barrierlayer being disposed on the second mirror layer.
 13. A method ofmanufacturing a mirror substrate, comprising: determining a firstthickness and a first material of a first mirror layer and a secondthickness and a second material of a second mirror layer; measuring aphase difference of reflected lights from the first mirror layer and thesecond mirror layer; determining a thickness of a phase compensationlayer based on the measured phase difference; forming first mirrorpatterns on a transparent substrate, each first mirror pattern includingthe phase compensation layer having the determined thickness and thefirst mirror layer made of the first material having the firstthickness; and forming the second mirror layer made of the secondmaterial having the second thickness on the transparent substrate andbetween neighboring ones of the first mirror patterns.
 14. The method ofclaim 13, wherein the first thickness of the first mirror layer isgreater than the second thickness of the second mirror layer.
 15. Themethod of claim 13, further comprising determining a thickness of acolor control layer between the second mirror layer and the transparentsubstrate, and wherein the thickness of the phase compensation layer isdetermined in consideration of a change of the phase difference due tothe color control layer.
 16. The method of claim 15, further comprising,before forming the second mirror layer, forming the color control layeron the transparent substrate and between the neighboring ones of thefirst mirror patterns, wherein a second mirror pattern includes thecolor control layer and the second mirror layer.
 17. A display device,comprising: a display substrate; a display unit on the displaysubstrate; and a mirror substrate facing the display substrate withrespect to the display unit, the mirror substrate including: atransparent substrate; a plurality of first mirror patterns arranged onthe transparent substrate and spaced apart from each other, each of thefirst mirror patterns including a phase compensation layer and a firstmirror layer sequentially stacked on the transparent substrate; and asecond mirror layer disposed on the transparent substrate and betweenneighboring ones of the first mirror patterns, the second mirror layerhaving a second thickness less than a first thickness of the firstmirror layer.
 18. The display device of claim 17, wherein the displayunit includes an emitting region including a pixel electrode and anemitting layer, and a non-emitting region, wherein the non-emittingregion overlaps the first mirror patterns, and the emitting regionoverlaps the second mirror layer.
 19. The display device of claim 18,wherein the mirror substrate further includes a color control layerinterposed between the transparent substrate and the second mirrorlayer.
 20. The display device of claim 19, wherein the first mirrorlayer includes aluminum (Al) or silver (Ag), the second mirror layerincludes Ag, the color control layer includes silicon oxide, and thephase compensation layer includes a transparent metal oxide.